Lovely topic, isn’t it? But if you’ve got a persistent case of diarrhea, it’s possible you picked up a parasite called Giardia during a summer swim. Giardia is transmitted by swallowing contaminated water (typically during a swim) or from other fecal-oral transmission (such as poor hand washing after changing baby diapers or using the restroom), or rarely, from contaminated food. Even if you are not a pool-water-mouth-squirter, it is very easy to accidentally swallow water while swimming- especially in a race! And diapered babies are supposed to be limited to a “baby pool” for a good reason, but think how often you have seen a busy mom change a diaper poolside (so she can multitask, watching her older child in the pool) and then hop right back in to the pool with her baby…probably thinking that the chlorine in the pool will “wash” her hands, if she is thinking about hygiene at all. Not infrequently we see clusters of giardia infections that can be traced to a public water source- a small lake or public pool, as well as deceptively pure-looking mountain streams.
Interestingly, only 25-50% of people who get infected notice any symptoms. If you do have symptoms, they tend to show up a week or two after exposure, and include persistent diarrhea (more than 5-7 days), bloating, flatulence, nausea and bad smelling stools.
Giardia infection is diagnosed most often by lab examination of stool samples, and often requires multiple samples to identify the parasite. The treatment is with antibiotics, and often people are treated based on clinical symptoms. Commonly people develop lactose intolerance following this infection, and therefore, avoiding dairy for a couple weeks after treatment is often helpful.
BOTTOM LINE: Watch your “bottom line” and remember not to routinely allow water in your mouth while swimming, plus don’t count on chlorine to be your sanitizer if you have just changed a diaper.